Andrés N. Robalino
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803826cdcd
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90 degree table rotations (clockwise and counter-clockwise) (#3086)
Also for 180 degree is expected. Rotation is not exactly like pivoting (transposing)
for instance, given the following table:
```
> echo [[col1, col2, col3]; [cell1, cell2, cell3] [cell4, cell5, cell6]]
───┬───────┬───────┬───────
# │ col1 │ col2 │ col3
───┼───────┼───────┼───────
0 │ cell1 │ cell2 │ cell3
1 │ cell4 │ cell5 │ cell6
───┴───────┴───────┴───────
```
To rotate it counter clockwise by 90 degrees, we can resort to first transposing (`pivot`)
them adding a new column (preferably integers), sort by that column from highest to lowest,
then remove the column and we have a counter clockwise rotation.
```
> echo [[col1, col2, col3]; [cell1, cell2, cell3] [cell4, cell5, cell6]] | pivot | each --numbered { = $it.item | insert idx $it.index } | sort-by idx | reverse | reject idx
───┬─────────┬─────────┬─────────
# │ Column0 │ Column1 │ Column2
───┼─────────┼─────────┼─────────
0 │ col3 │ cell3 │ cell6
1 │ col2 │ cell2 │ cell5
2 │ col1 │ cell1 │ cell4
───┴─────────┴─────────┴─────────
```
Which we can get easily, in this case, by doing:
```
> echo [[col1, col2, cel3]; [cell1, cell2, cell3] [cell4, cell5, cell6]] | rotate counter-clockwise
───┬─────────┬─────────┬─────────
# │ Column0 │ Column1 │ Column2
───┼─────────┼─────────┼─────────
0 │ col3 │ cell3 │ cell6
1 │ col2 │ cell2 │ cell5
2 │ col1 │ cell1 │ cell4
───┴─────────┴─────────┴─────────
```
There are also many powerful use cases with rotation, it makes a breeze creating tables with many columns, say:
```
echo 0..12 | rotate counter-clockwise | reject Column0
───┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┬──────────┬──────────┬──────────┬──────────
# │ Column1 │ Column2 │ Column3 │ Column4 │ Column5 │ Column6 │ Column7 │ Column8 │ Column9 │ Column10 │ Column11 │ Column12 │ Column13
───┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┼──────────┼──────────┼──────────┼──────────
0 │ 0 │ 1 │ 2 │ 3 │ 4 │ 5 │ 6 │ 7 │ 8 │ 9 │ 10 │ 11 │ 12
───┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┴──────────┴──────────┴──────────┴──────────
```
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2021-02-22 06:56:34 -05:00 |
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